1. Field of the Invention
The present invention relates generally to image reproduction machines, and more particularly relates to paper supply feed systems for image reproduction machines such as printers and copiers.
2. Description of Related Art
It is conventional practice to provide image reproduction machines, such as printers and copiers, with a paper feed supply tray configured to hold a stack of cut paper sheets. The paper-filled tray is typically inserted into an appropriate slot formed in the machine housing to position the paper stack adjacent a picker roller assembly which is selectively operable to sequentially feed the paper sheets, top sheet first, into the paper feed path of the machine. To accomplish this task, the picker roller portion of the assembly is normally positioned above the top paper sheet in the stack, and is movable downwardly into frictional engagement therewith and rotationally drivable to move the top sheet into the feed path.
To enlarge the overall supply paper holding capacity in image reproduction machines of this general type, and/or permit the use of different sized paper sheets therein without reloading, various proposals have been previously made to provide printers and copiers with a plurality of paper feed trays which may be operatively inserted into corresponding slots in the machine housing in a vertically stacked and mutually spaced apart relationship. In this manner, the paper sheets in any selected one of the various trays may be fed into the machine, thereby permitting much longer printing runs without reloading a paper tray (when two or more of the trays are loaded with the same size paper), or permitting changes in the paper size being fed into the machine without changing out the paper size in a tray (when different size paper is loaded into two or more of the trays).
While this vertical stacking of multiple paper feed trays is a conventional and widely accepted practice, it is subject to several well known problems, limitations and disadvantages. For example, using this vertically stacked feed tray arrangement has heretofore required a separate picker roller assembly for each paper tray-a requirement adding considerable complexity and additional fabrication cost to the overall image reproduction machine.
Moreover, this conventional stacked tray configuration can require an undesirable, and otherwise unnecessary, height increase in the machine housing. This is due to the fact that each picker roller assembly must be disposed directly above the top sheet of paper in its associated paper feed tray, and directly beneath the next higher tray in the stack. Accordingly, for example, if there are four vertically stacked trays, each having an associated picker roller assembly, the total tray/picker roller assembly height required would be 4T+4P, "T" being the height of each tray, and "P" being the total vertical distance required for each picker roller assembly. Further, it is typically necessary to route the paper sheets picked from the individual, vertically spaced paper stacks through different paper feed paths in the machine housing, thereby additionally increasing the overall complexity and fabrication cost of the image reproduction machine.
It can readily be seen from the foregoing that it would be desirable to provide an image reproduction machine, such as a printer or copier, with an improved multiple tray paper feed system which eliminates or at least substantially reduces the above-mentioned problems, limitations and disadvantages heretofore associated with vertically stacked paper tray systems of the general type described above.